| UCBLogo | — | — | dynamic typing | — |
| UCSD Pascal | 1978 | — | — | 1 |
| Uiua | — | tacit programming, array programming, stack-oriented programming | — | — |
| Umple | 2008 | object-oriented programming | static typing | — |
| UNCOL | 1958 | — | — | — |
| UNICODE | 1957 | — | — | — |
| Unicon | — | procedural programming, object-oriented programming | — | — |
| Uniface | 1984 | three schema approach | — | — |
| Unified Parallel C | 1999 | parallel computing | manifest typing, weak typing | — |
| Unlambda | 1999 | functional programming, esoteric programming | — | — |
| UnrealScript | 1998 | generic programming, object-oriented programming | static typing, safe typing, strong typing | — |
| Ur/Web | 2014 | — | — | — |
| URBI | 2003 | — | — | — |
| Urbiscript | — | object-oriented programming | dynamic typing, duck typing | — |
| UrduScript | — | — | — | — |
| Uxntal | — | — | — | — |